I cannot seem to get the right answer.
Animal Pulse Rate According to one model, an animalís heart rate varies according to its weight. The formula N(w)=885w^-1/2 gives an estimate for the
average number N of beats per minute for an animal that weighs w pounds. Use the formula to estimate the heart rate for a horse that weighs 800 pounds. To be brutally honest I cannot get this right at all.